To determine the predominant staphylococcal cassette chromosome (SCC) mec element in methicillin-resistant Staphylococcus aureus, we typed 190 isolates from a hospital in Taiwan. We found a shift from type IV to type III SCCmec element during 1992–2003, perhaps caused by selective pressure from indiscriminate use of antimicrobial drugs.
Methicillin-resistant Staphylococcus aureus; multilocus sequence typing; SCCmec; dispatch
Clinical and laboratory data on severe acute respiratory syndrome (SARS), particularly on the temporal progression of abnormal laboratory findings, are limited. We conducted a prospective study on the clinical, radiologic, and hematologic findings of SARS patients with pneumonia, who were admitted to National Taiwan University Hospital from March 8 to June 15, 2003. Fever was the most frequent initial symptom, followed by cough, myalgia, dyspnea, and diarrhea. Twenty-four patients had various underlying diseases. Most patients had elevated C-reactive protein (CRP) levels and lymphopenia. Other common abnormal laboratory findings included leukopenia, thrombocytopenia, and elevated levels of aminotransferase, lactate dehydrogenase, and creatine kinase. These clinical and laboratory findings were exacerbated in most patients during the second week of disease. The overall case-fatality rate was 19.7%. By multivariate analysis, underlying disease and initial CRP level were predictive of death.
severe acute respiratory syndrome; C-reactive protein; intravenous immunoglobulin
Thirty-one cases of severe acute respiratory syndrome (SARS) occurred after exposure in the emergency room at the National Taiwan University Hospital. The index patient was linked to an outbreak at a nearby municipal hospital. Three clusters were identified over a 3-week period. The first cluster (5 patients) and the second cluster (14 patients) occurred among patients, family members, and nursing aids. The third cluster (12 patients) occurred exclusively among healthcare workers. Six healthcare workers had close contact with SARS patients. Six others, with different working patterns, indicated that they did not have contact with a SARS patient. Environmental surveys found 9 of 119 samples of inanimate objects to be positive for SARS coronavirus RNA. These observations indicate that although transmission by direct contact with known SARS patients was responsible for most cases, environmental contamination with the SARS coronavirus may have lead to infection among healthcare workers without documented contact with known hospitalized SARS patients.
Severe acute respiratory syndrome; healthcare workers; environmental contamination; real-time reverse transcriptase–polymerase chain reaction
SARS; atypical presentation; temporary defervescence
Outbreaks of sexually transmitted hepatitis C virus (HCV) infections have been recently reported in HIV-infected men who have sex with men (MSM) in Europe, Australia, and North America. Little is known concerning whether this also occurs in other Asia-Pacific countries. Between 1994 and 2010, a prospective observational cohort study was performed to assess the incidence of recent HCV seroconversion in 892 HIV-infected patients (731 MSM and 161 heterosexuals) who were not injecting drug users. A nested case-control study was conducted to identify associated factors with recent HCV seroconversion, and phylogenetic analysis was performed using NS5B sequences amplified from seroconverters. During a total followup duration of 4,270 person-years (PY), 30 patients (3.36%) had HCV seroconversion, with an overall incidence rate of 7.03 per 1,000 PY. The rate increased from 0 in 1994 to 2000 and 2.29 in 2001 to 2005 to 10.13 per 1,000 PY in 2006 to 2010 (P < 0.05). After adjustment for age and HIV transmission route, recent syphilis remained an independent factor associated with HCV seroconversion (odds ratio, 7.731; 95% confidence interval, 3.131 to 19.086; P < 0.01). In a nested case-control study, seroconverters had higher aminotranferase levels and were more likely to have CD4 ≥ 200 cells/μl and recent syphilis than nonseroconverters (P < 0.05). Among the 21 patients with HCV viremia, phylogenetic analysis revealed 7 HCV transmission clusters or pairs (4 within genotype 1b, 2 within genotype 2a, and 1 within genotype 3a). The incidence of HCV seroconversion that is associated with recent syphilis is increasing among HIV-infected patients in Taiwan.
Acinetobacter baumannii complex (ABC) has emerged as an important pathogen causing a variety of infections. Longitudinal multicenter surveillance data on ABC from different sources in Taiwan have not been published. Using data from the Taiwan Surveillance of Antimicrobial Resistance (TSAR) conducted biennially, we investigated the secular change in resistance of 1640 ABC from 2002 to 2010 (TSAR period III to VII) to different antimicrobial agents and identified factors associated with imipenem-resistant and extensively drug-resistant ABC (IRABC and XDRABC).
Isolates were collected by TSAR from the same 26 hospitals located in all 4 regions of Taiwan. Minimum inhibitory concentrations (MIC) were determined by reference broth microdilution method. Isolates nonsusceptible to all tested aminoglycosides, fluoroquinolones, β-lactam, β-lactam/β-lactam inhibitors, and carbapenems were defined as extensively drug-resistant (XDR). Multivariate logistic regression analysis was performed to assess the relationship between predictor variables among patients with resistant ABC and patients with non-resistant ABC.
The prevalence of IRABC increased from 3.4% in 2002 to 58.7% in 2010 (P < 0.001; odds ratio [OR], 2.138; 95% confidence interval [CI], 1.947 to 2.347) and that of XDRABC increased from 1.3% in 2002 to 41.0% in 2010 (P < 0.001; OR, 1.970; 95% CI, 1.773-2.189). The rates of non-susceptibility to other antimicrobial agents remained high (>55%) over the years with some fluctuations before and after TSAR V (2006) on some agents. Multivariate analysis revealed that recovery from elderly patients, origins other than blood, from ICU settings, or geographic regions are independent factors associated with IRABC and XDRABC. Although the prevalence of XDRABC increased in all four regions of Taiwan over the years, central Taiwan had higher prevalence of XDRABC starting in 2008. Susceptibility to polymyxin remained high (99.8%).
This longitudinal multicenter surveillance program revealed significant increase and nationwide emergence of IRABC and XDRABC in Taiwan over the years. This study also identified factors associated with IRABC and XDRABC to help guide empirical therapy and at-risk groups requiring more intense interventional infection control measures with focused surveillance efforts.
Extensively drug-resistant; Acinetobacter baumannii complex; Antimicrobial resistance
This case-control study aimed to characterize the factors associated with amebiasis, defined as presence of anti-Entamoeba histolytica antibody titers of ≧ 128 by indirect hemagglutination assay, among persons seeking voluntary counseling and testing (VCT) for human immunodeficiency virus (HIV) infection. Between April 2006 and September 2009, 57 of 4,802 persons (1.2%) seeking VCT services were seropositive for E. histolytica infection. Compared with 228 seronegative controls, case subjects were older (odds ratio [OR] for per 1-year increase, 1.098; 95% confidence interval [CI], 1.036, 1.165), less likely to hold bachelor degree or higher (OR, 0.359; 95% CI, 0.152, 0.846), and were more likely to be men who have sex with men (MSM) (OR, 8.382; 95% CI, 2.050, 34.266) and have oral-anal sex (OR, 4.016; 95% CI, 1.711, 9.427) in multiple logistic regression analysis. The MSM, fecal-oral contamination, lower educational achievement, and older age were associated with increased risk for amebiasis among persons seeking VCT for HIV infection.
Acinetobacter baumannii has emerged as a significant nosocomial pathogen worldwide. The increasing trend of carbapenem and fluoroquinolone resistance in A. baumannii severely limits the usage of therapeutic antimicrobial agents. Here we report the genome sequence of a multidrug-resistant A. baumannii strain, TCDC-AB0715, harboring both blaOXA-23 and blaOXA-66.
An outbreak of human immunodeficiency virus (HIV) infection occurred among injecting drug users (IDU) in Taiwan between 2003 and 2006, when an extremely high prevalence of hepatitis C virus (HCV) infection was also detected. To determine whether clusters of hepatitis D virus (HDV) infection occurred in this outbreak, 4 groups of subjects were studied: group 1, HIV-infected IDU (n = 904); group 2, HIV-infected non-IDU (n = 880); group 3, HIV-uninfected IDU (n = 211); and group 4, HIV-uninfected non-IDU (n = 1,928). The seroprevalence of hepatitis B virus (HBV) was 19.8%, 18.4%, 17.1%, and 6.7%, and HDV seroprevalence among HBV carriers was 75.4%, 9.3%, 66.7%, and 2.3%, for groups 1, 2, 3, and 4, respectively. Ninety-nine of 151 (65.6%) HDV-seropositive IDU had HDV viremia: 5 were infected with HDV genotype I, 41 with genotype II, 51 with genotype IV, and 2 with genotypes II and IV. In the phylogenetic analysis, only one cluster of 4 strains within the HDV genotype II was identified. Among patients with HCV viremia, a unique cluster within genotype 1a was observed; yet, patients within this cluster did not overlap with those observed in the HDV phylogenetic analysis. In summary, although IDU had a significantly higher HDV seroprevalence, molecular epidemiologic investigations did not support that HDV was introduced at the same time as HCV among IDU.
The incidence of and risk factors for acquiring community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) among patients staying in intensive care units (ICUs) remain unclear. We enrolled patients staying in two ICUs at the Far Eastern Memorial Hospital during the period of 1 September 2008 to 30 September 2009 to clarify this issue. Surveillance cultures for MRSA were taken from nostril, sputum or throat, axillae, and the inguinal area in all enrolled patients upon admission to the ICU, every 3 days thereafter, and on the day of discharge from the ICU. For each MRSA isolate, we performed multilocus sequence typing, identified the type of staphylococcal cassette chromosome mec, detected the presence of the Panton-Valentine leukocidin gene, and conducted drug susceptibility tests. Among the 1,906 patients who were screened, 203 patients were carriers of MRSA before their admission to the ICU; 81 patients acquired MRSA during their stay in the ICU, including 31 who acquired CA-MRSA. The incidence rates of newly acquired MRSA and CA-MRSA during the ICU stay were 7.9 and 3.0 per 1,000 patient-days, respectively. Prior usage of antipseudomonal penicillins and antifungals and the presence of a nasogastric tube were found to be independent risk factors for acquiring CA-MRSA during the ICU stay when data for CA-MRSA carriers and patients without carriage of MRSA were compared (P = 0.0035, 0.0330, and 0.0262, respectively). Prior usage of carbapenems was found to be a protective factor against acquiring CA-MRSA when data for patients with CA-MRSA and those with health care-associated MRSA acquired during ICU stay were compared (P = 0.0240).
While quantification of viral loads has been successfully employed in clinical medicine and has provided valuable insights and useful markers for several viral diseases, the potential of measuring bacterial DNA load to predict outcome or monitor therapeutic responses remains largely unexplored. We tested this possibility by investigating bacterial loads in Acinetobacter baumannii bacteremia, a rapidly increasing nosocomial infection characterized by high mortality, drug resistance, multiple and complicated risk factors, all of which urged the need of good markers to evaluate therapeutics.
Methods and Findings
We established a quantitative real-time PCR assay based on an A. baumannii-specific gene, Oxa-51, and conducted a prospective study to examine A. baumannii loads in 318 sequential blood samples from 51 adults patients (17 survivors, 34 nonsurvivors) with culture-proven A. baumannii bacteremia in the intensive care units. Oxa-51 DNA loads were significantly higher in the nonsurvivors than survivors on day 1, 2 and 3 (P = 0.03, 0.001 and 0.006, respectively). Compared with survivors, nonsurvivors had higher maximum Oxa-51 DNA load and a trend of increase from day 0 to day 3 (P<0.001), which together with Pitt bacteremia score were independent predictors for mortality by multivariate analysis (P = 0.014 and 0.016, for maximum Oxa-51 DNA and change of Oxa-51 DNA, respectively). Kaplan-Meier analysis revealed significantly different survival curves in patients with different maximum Oxa-51 DNA and change of Oxa-51 DNA from day 0 to day 3.
High Oxa-51 DNA load and its initial increase could predict mortality. Moreover, monitoring Oxa-51 DNA load in blood may provide direct parameters for evaluating new regimens against A. baumannii in future clinical studies.
Multidrug-resistant (MDR) Acinetobacter spp. have emerged as a threat to public health. We investigated the various genes involved in resistance to fluoroquinolones, aminoglycosides, cephalosporins, and carbapenems in 75 clinical Acinetobacter isolates from a Taiwanese hospital. All isolates were tested for the gyrA mutations, the presence of integrons, blaAmpC, and carbapenem resistance genes. The Ser83Leu mutation in GyrA accounted for fluoroquinolone resistance. The presence of integrons containing aminoglycoside-modifying enzymes was associated with resistance to gentamicin and tobramycin but not with resistance to amikacin. The presence of an ISAba1 element upstream of blaAmpC was correlated with cephalosporin resistance. Although most Acinetobacter baumannii isolates with ISAba1-blaOXA-51-like were resistant to carbapenems, several isolates remained susceptible to carbapenems. Transformation by the introduction of ISAba1-blaOXA-23 or ISAba1-blaOXA-66 into A. baumannii ATCC 15151 (CIP 70.10), resulting in the overexpression of OXA-23 or OXA-66, respectively, suggested the role of the ISAba1 element as a strong promoter. The two transformants showed significantly increased resistance to piperacillin-tazobactam, imipenem, and meropenem. The cefepime resistance conferred by ISAba1-blaOXA-23 and the impact of ISAba1-blaOXA-66 on carbapenem resistance in A. baumannii are reported here for the first time. Continuous surveillance of antibiotic resistance genes in MDR Acinetobacter spp. and elucidation of their antibiotic resistance mechanisms are crucial for the development of therapy regimens and for the prevention of further dissemination of these antibiotic resistance genes.
Previous studies regarding the prognosis of patients infected with MRSA isolates characterized by a high minimum inhibitory concentration (MIC) for vancomycin have generally used a commercial Etest. Little research has been conducted on determining the vancomycin susceptibility of MRSA using a reference microdilution. Additionally, there is discordance between the MIC result from an Etest and the value determined using the reference microdilution method.
Using a reference microdilution method, we determined the MIC of vancomycin for isolates from 123 consecutive patients with nosocomial MRSA bacteremia. The clinical features and outcome for these patients were recorded and the MRSA isolates were genotyped.
Among the 123 non-duplicated isolates, 21.1% had a MIC = 2 mg/L, 76.4% had a MIC = 1 mg/L and 2.4% had MIC = 0.5 mg/L. Patients with MRSA bacteremia in the ICU or those who had been hospitalized for a long time were more likely to be infected with strains of high vancomycin MIC MRSA (MIC = 2 mg/L; p < 0.05). Cox regression analysis demonstrated that the high MIC group had a significantly higher 30-day mortality than the low MIC group (HR: 2.39; 95% CI: 1.20-4.79; p = 0.014). Multivariate analyses indicated that the presence of high MIC isolates, pneumonia, post-cardiothoracic surgery and a high Charlson comorbidity index were all independent predictors of a 30-day mortality. Genotyping of these high vancomycin MIC isolates demonstrated that SCCmec III, spa type037, was the predominant strain (> 80%). The rates of resistance to trimethoprim/sulfamethoxazole, gentamicin, levofloxacin, rifampin and tetracycline were also higher in the high MIC group than in the isolates belonging to low MIC group (p < 0.05).
In a high vancomycin MIC group in Taiwan, SCCmec III, spa type t037, was the predominant strain of MRSA identified. Patients with MRSA bacteremia in the ICU or who had prolonged hospitalization were more likely to be infected with S. aureus strains with high vancomycin MICs. The mortality rate was higher among patients infected with these strains compared to patients infected with low MIC strains.
This study was designed to determine the strength of the association between the isolation of nonfermentative gram-negative bacilli (NFGNB) from tap water faucet aerators and the prevalence of colonization or infection of patients in intensive care units (ICUs). Surveillance cultures were obtained during a 4-month period from 162 faucet aerators located in seven different ICUs. The prevalence of colonization or infection of ICU patients with NFGNB was determined by prospective surveillance during the same period. Fifty four (33%) of the faucet aerators contained NFGNB. Among the 66 NFGNB isolated from faucet aerators, the most frequently encountered ones were Sphingomonas paucimobili (26 isolates), Pseudomonas aeruginosa (14 isolates), Chryseobacterium meningosepticum (13 isolates), Achromobacter xylosoxidans (6 isolates), Burkholderia cepacia (4 isolates), and Stenotrophomonas maltophilia (3 isolates). Acinetobacter baumannii was not recovered. The most common NFGNB isolated from ICU patients were P. aeruginosa and A. baumannii. There was a significant correlation between the overall prevalence of NFGNB in faucet aerators and their prevalence in exposed ICU patients (Spearman r = 0.821, P = 0.02). There was also a significant correlation between the prevalence of C. meningosepticum in faucet aerators and its prevalence among ICU patients (Spearman r = 0.847, P = 0.016). The electrokaryotypes of four clinical isolates of C. meningosepticum were similar to those of faucet isolates. Measures directed at making the water supply safe may prevent infection by C. meningosepticum and other waterborne pathogens.
Molecular epidemiological definitions that are based on staphylococcal cassette chromosome mec (SCCmec) typing and phylogenetic analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolates are considered a reliable way to distinguish between healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA). However, there is little information regarding the clinical features and outcomes of bacteremia patients with MRSA carrying different SCCmec types.
From January 1 through December 31, 2006, we recorded the demographic data and outcomes of 159 consecutive adult MRSA bacteremia patients from whom isolates for SCCmec analysis were collected. All participants were patients at a tertiary care center in Taiwan.
The following SCCmec types were identified in MRSA isolates: 30 SCCmec II (18.9%), 87 SCCmec III (54.7%), 22 SCCmec IV (13.8%), and 20 SCCmec V (12.6%). The time from admission to the first MRSA-positive blood culture for patients infected with isolates with the SCCmec III element (mean/median, 50.7/26 days) was significantly longer than for patients infected with isolates carrying SCCmec IV or V (mean/median, 6.7/3 days for SCCmec IV; 11.1/10.5 days for SCCmec V) (P<0.05). In univariate analysis, community onset, soft tissue infection, and deep-seated infection were predictors for SCCmec IV/V. In multivariate analysis, length of stay before index culture, diabetes mellitus, and being bedridden were independent risk factors associated with SCCmec II/III.
These findings are in agreement with previous studies of the genetic characteristics of CA-MRSA. MRSA bacteremia with SCCmec II/III isolates occurred more among patients with serious comorbidities and prolonged hospitalization. Community onset, skin and soft tissue infection, and deep-seated infection best predicted SCCmec IV/V MRSA bacteremia.
In order to determine the prevalence of methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) colonization among adults in community settings in Taiwan and identify its risk factors, we conducted the present study. For a 3-month period, we enrolled all adults who attended mandatory health examinations at three medical centers and signed the informed consent. Nasal swabs were taken for the isolation of S. aureus. For each MRSA isolate, we performed multilocus sequence typing, identification of the staphylococcal cassette chromosome mec, tests for the presence of the Panton-Valentine leukocidin gene, and tests for drug susceptibilities. Risk factors for MRSA colonization were determined. The results indicated that the MRSA colonization rate among adults in the community settings in Taiwan was 3.8% (119/3,098). Most MRSA isolates belonged to sequence type 59 (84.0%). Independent risk factors for MRSA colonization included the presence of household members less than 7 years old (P < 0.0001) and the use of antibiotics within the past year (P = 0.0031). Smoking appeared to be protective against MRSA colonization (P < 0.0001).
Nosocomial infections caused by antibiotic-resistant Klebsiella pneumoniae are emerging as a major health problem worldwide, while community-acquired K. pneumoniae infections present with a range of diverse clinical pictures in different geographic areas. In particular, an invasive form of K. pneumoniae that causes liver abscesses was first observed in Asia and then was found worldwide. We are interested in how differences in gene content of the same species result in different diseases. Thus, we sequenced the whole genome of K. pneumoniae NTUH-K2044, which was isolated from a patient with liver abscess and meningitis, and analyzed differences compared to strain MGH 78578, which was isolated from a patient with pneumonia. Six major types of differences were found in gene clusters that included an integrative and conjugative element, clusters involved in citrate fermentation, lipopolysaccharide synthesis, and capsular polysaccharide synthesis, phage-related insertions, and a cluster containing fimbria-related genes. We also conducted comparative genomic hybridization with 15 K. pneumoniae isolates obtained from community-acquired or nosocomial infections using tiling probes for the NTUH-K2044 genome. Hierarchical clustering revealed three major groups of genomic insertion-deletion patterns that correlate with the strains' clinical features, antimicrobial susceptibilities, and virulence phenotypes with mice. Here we report the whole-genome sequence of K. pneumoniae NTUH-K2044 and describe evidence showing significant genomic diversity and sequence acquisition among K. pneumoniae pathogenic strains. Our findings support the hypothesis that these factors are responsible for the changes that have occurred in the disease profile over time.
We describe a previously healthy patient with chronic otitis media complicated with cerebellar abscess caused by Tsukamurella tyrosinosolvens. The organism was identified based on conventional biochemical identification methods, PCR-restriction fragment length polymorphism analysis of the hsp65 gene, and 16S rRNA gene sequencing. The patient was treated successfully with debridements and prolonged antibiotic therapy.
Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is known to be a poor prognostic factor. While several PCR assays for the detection of MRSA in various clinical samples were recently reported, the possibility that a quantitative PCR assay could be used to quantify and monitor MRSA bacteremia has not been explored. In this study, we established a quantitative real-time PCR assay for the mecA gene using known copy numbers of a plasmid containing mecA DNA as a standard and the previously described mecA-specific primers and probe (P. Francois et al., J. Clin. Microbiol. 41:254-260, 2003). We employed this assay to examine 250 sequential whole-blood samples from 20 adult patients, including 13 survivors and 7 nonsurvivors, with culture-proven MRSA bacteremia at the intensive care units of National Taiwan University Hospital between 1 July 2006 and 31 January 2007. The levels of mecA DNA in the nonsurvivors were significantly higher than those in the survivors during the three periods of bacteremia examined (days 0 to 2, 3 to 5, and 6 to 8) (P = 0.003 by two-tailed Mann-Whitney U test). Moreover, the nonsurvivors had higher mecA DNA levels than the survivors after 3 days and 7 days of anti-MRSA therapy (medians for nonsurvivors and survivors at 3 days, 5.86 and 4.30 log copies/ml, respectively; medians for nonsurvivors and survivors at 7 days, 5.21 and 4.36 log copies/ml, respectively; P = 0.02 and P = 0.04, respectively, by two-tailed Mann-Whitney U test). Together, these findings suggest that the level of mecA DNA in blood could potentially be used to monitor MRSA bacteremia and evaluate responses to therapy.
Tipranavir (TPV) is a recently approved nonpeptidic protease inhibitor (PI) of HIV-1 and has been indicated for those infected with PIs-resistant HIV-1. However, in clinical practice, whether the HIV-1 from the patients with virological failure to the regimens containing first-line PIs remains susceptible to TPV/r may be questionable.
To assess the resistance levels to TPV of HIV-1 from patients with treatment failure to first-line PIs, patients who experienced virological failure were tested for genotypic resistance of HIV-1 since August 2006 in National Taiwan University Hospital. Patients were enrolled for this analysis if their failed regimens contained > 12 weeks of atazanavir or lopinavir/ritonavir (defined as ATV group and LPV/r group, respectively), but were excluded if they experienced both or other PIs. The levels of genotypic resistance to TPV/r were determined by TPV mutation score.
Till May 2008, 21 subjects in ATV group and 20 subjects in LPV/r group were enrolled. The TPV mutation scores in subjects in LPV/r group were significantly higher than these in ATV group (median, 3 vs 1, P = 0.007). 95.2% subjects in ATV group and only 45% subjects in LPV/r group had an estimated maximal virological response to TPV/r (P < 0.001). The resistance levels to TPV/r correlated with the duration of exposure to first-line PIs, whether in ATV or LPV/r group.
Cross-resistance from first-line PIs may impede the effectiveness of TPV/r-containing salvage therapy. TPV/r should be used cautiously for patients with virological failure to LPV/r especially long duration of exposure.
Among 345 persons who underwent indirect hemagglutination (IHA) serological assays and assays of specific amebic antigens in their stool samples, 24 of 36 (66.7%) who were seropositive for Entamoeba histolytica had intestinal amebiasis as determined by antigen assays compared with 2 of 309 (0.2%) who were seronegative (odds ratio, 307; 95% confidence interval, 64.9 to 1,451). The estimated cost to detect a case of intestinal amebiasis by serology followed by antigen assays ($52) could be reduced by 74.3% and 69.9%, respectively, compared with the costs of the concurrent use of both assays ($202) and the antigen assays alone ($173). Our finding suggests that IHA assays followed by specific-amebic-antigen assays can be cost-effective in the diagnosis of intestinal amebiasis among persons with or without human immunodeficiency virus infection who are at risk for E. histolytica infection.
We report 5 years’ surveillance data from the Taiwan Centers for Disease Control on unexplained deaths and critical illnesses suspected of being caused by infection. A total of 130 cases were reported; the incidence rate was 0.12 per 100,000 person-years; and infectious causes were identified for 81 cases (62%).
Cause of death; autopsy; Taiwan; infection; bacteria; viruses; dispatch
Acinetobacter spp. have emerged as important nosocomial and multidrug-resistant pathogens in the last decade. A. calcoaceticus, A. baumannii, Acinetobacter genospecies 3, and Acinetobacter genospecies 13TU are genetically closely related and are referred to as the A. calcoaceticus-A. baumannii complex (ACB complex). Distinct Acinetobacter spp. may be associated with differences in antimicrobial susceptibility, so it is important to identify Acinetobacter spp. at the species level. We developed a microsphere-based array that combines an allele-specific primer extension assay and microsphere hybridization for the identification of Acinetobacter spp. This assay can discriminate the 13 different Acinetobacter spp. in less than 8.5 h, and it has high specificity without causing cross-reactivity with 14 other common nosocomial bacterial species. The sensitivity of this assay was 100 A. baumannii cells per ml of blood, and it could discriminate multiple species in various mixture ratios. The developed assay could differentiate clinical Acinetobacter spp. isolates with a 90% identification rate. The antimicrobial susceptibility test showed that A. baumannii isolates were resistant to most antimicrobial agents other than imipenem, while the genospecies 3 and 13TU isolates were more susceptible to most antimicrobial agents, especially ciprofloxacin and ampicillin-sulbactam. These results supported the idea that this assay possibly could be applied to clinical samples and provide accurate species identification, which might be helpful for clinicians when they are treating infections caused by Acinetobacter spp.
Invasive amebiasis is an emerging parasitic disorder in Taiwan, especially in patients diagnosed with human immunodeficiency virus (HIV) infection. Thirty-three Taiwanese subjects with amebic liver abscess (ALA) were examined and a possible correlation between ALA and HIV infection was investigated.
Among ALA patients, the proportion of HIV-positive individuals increased during the study period. ALA was the first major clinical presentation in 54% of HIV patients with ALA. Overall, 58% (14/24) of HIV-infected patients had a CD4+ count > 200 cells/μL and 82.1% (23/28) had no concurrent opportunistic infection or other evidence of HIV infection. There was no marked difference in clinical characteristics between HIV-positive and HIV-negative ALA patients except the level of leukocytosis.
While the clinical characteristics described herein cannot be used to determine whether ALA patients have HIV infection, routine HIV testing is recommended in patients with ALA, even in the absence of HIV symptoms.